Updater (cmd-line): hide the WebDAV password when uploading

For convenience, we allow the WebDAV password to be stored
in the 'upload host' part of the upload site information:
webdav:<username>:<password>. However, we also showed the complete
upload host line in the progress when uploading -- particularly
inconvenient when uploading from a Jenkins job whose console output
is visible to everybody.

Special-case webdav to hide the password, with the intention of
deprecating that feature in favor of a $HOME/.netrc based solution.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Add a .netrc parser

We will use this in the WebDAV uploader to avoid storing credentials in
Jenkins jobs' configurations.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Add unit tests for the .netrc parser

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Make the location of $HOME/.netrc overrideable

The property 'webdav.netrc' can be used to override the path of the
.netrc file to use.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
WebDAV uploader: heed $HOME/.netrc

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Updater (cmd-line): interactive prompt requires a console

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'webdav-uploader-fixes'

This should help with upload credentials in the Jenkins jobs...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>